Hi,
I finally got a Billet Design hydroclutch installed in my 1977 sportster and the lever is very, very hard to pull. I realize that this item isn't designed to necessarily lighten the pull but it's worse than the pull when I had a cable so sussing out suggestions. Any ideas as to why, or what I could do to decrease the amount of pressure the lever needs to push the plunger in?

I had some adjustment problems at first because my clutch plates were stuck a bit originally, so I kept futzing with it. Now, after getting them unstuck, the clutch seems to work as specified, although I'm getting some clutch slippage if I rev the bike while riding. I'll ask this in a different thread I guess, but I know I put a bit too much oil in the primary when i was filling it, and I think the 20/40 Pennzoil may be too slick and synthetic anyway.

Make sure the master is the right match to work the slave. The slave cylinder bore is usually larger than the master. There are formulas out there to work out the ratios, 1" slave and 1" master equal 1:1 ratio. Smaller master bores give less slave piston travel but with more force.
If the bores aren't compatible you'll need a come-along to pull the lever.

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"If a camel flies, no one will laugh if it doesn't get very far".

I see that you bought the master cylinder and hydroclutch as a kit, it isn't likely to be a mismatched system then. The first thing that I would do is remove the plunger assy from the primary cover, and operate it with the unit detached. This will tell you whether the lever is hard to pull under a no load condition. If it is NOT hard to operate, then the fault lies within the clutch basket. If it IS hard to pull, then you'll need to examine every component within the hydraulic side, ensuring that all parts are free from damage and are assembled correctly. There may be some info somewhere about how much you should expect the piston to travel with one full pull on the lever. Keywords with any hydraulic system, " Scrupulously clean"
I suspect from what you said about the plates being stuck that the hydraulic side of the system will be fine. I'm very keen to find out what you do and what the results are because I'm thinking about upgrading my clutch with the same kit. Good luck.

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Better a bottle in front of me than a frontal lobotomy.

Thanks for all the advice guys. I'm planning on grabbing the right oil and working this out over the weekend. The reason I decided to try our this clutch system was it had a number of good reviews on the forum and because I've always had issues with the clutch on this bike. I've had it since about 1989 but it was mothballed in my mother's barn for about 15 years after I went overseas and left it with a friend for safekeeping (and that didn't happen). I'm not a mechanic but somewhat mechanically inclined so I've just been slowly working on it and, frankly, fixing things that were done in a half-ass way by a mechanic. I can say two things about the system so far: 1. Billet Design has been very responsive to all my often inane questions and 2. Over the short time I've used the hydraulic clutch, it has worked much more smoothly than the ramp system. The clutch engages and disengages well; there's no more incessant fiddling with the adjustment to get it not to want to creep but still engage correctly.

What I don't like about the system so far is that the pull does seem harder. Billet says it shouldn't though, and I think part of the problem is the lever on the master being a different design than what I'm used to and the reach being off. I'm trying to order a different lever from Hog Lever but they want the model number of the lever to be replaced (says there is too much variation) and I don't see one. I'm getting the PN number of the unit from Billet though, which might help.

A few general points:
Reducing the master cylinder bore will make the lever easier to pull, but it will need to move a greater distance in order to shift the same amount of fluid as its larger bore cousin.
The master cylinder should, by design, have the capacity to shift a greater volume of fluid than the slave, that way, the full range ( stroke ) of the slave cylinder is ensured.
When we are dealing with motorcycle hydraulics, we only have muscle power available, be it from our fingers, or a leg, so the system designer has to ensure that muscle power alone is capable of operating the system. This he achieves by using levers and associated fulcrum to push the piston and ram, into the trapped body of fluid. This is what creates the pressure.
Careful consideration is prudent therefore, if we are going to mix and match hydraulic system components. It's all solvable if you do the math!